Spacer applying tool



6 w. N. KOELLER 6 38 SPACER APPLYING TOOL Filed Nov. 29, 1961 United States Patent 3,152,938 SPACER A1PLY1NG TOOL William N. Koeller, Birmingham, Mich, assignor to Huck Manufacturing Company, Detroit, Mich, a corporation of Michigan Ffled Nov. 29, 1961, Ser. No. 155,775 6 Claims. (Cl. 29-427) This invention relates to apparatus and method for assembling a coiled spacer in between a pair of spaced laminae.

The tool and method of this invention is a modification and an improvement of that shown in my copending application, Serial No. 43,452, filed July 18, 1960, now Patent No. 3,105,291, issued October 1, 1963. More specifically, the tool and method of this invention apply to the art of securing, by means of fasteners, various members to structural sandwiches of the type having relatively high strength skins or laminae spaced apart by a relatively weak, low density core. In practice, a hole is first drilled through the laminae and the core and a portion of the core surrounding the opening is removed in order to facilitate the insertion of a helically wound spacer between the laminae and internally about the periphery of the bores in the laminae. The spacer has an inside diameter substantially the same as the diameter of the bores through the laminae. The outside diameter is greater, of course, and, hence, reinforces axially the area radially proximate to the bores. By so axially reinforcing the area around the bores, various structure can be secured to the sandwich by means of a fastener extending through the hole; in other words, the spacer prevents the sandwich from axially collapsing. In order to provide for a relatively uniform bearing surface between the helically wound spacer and the internal surfaces of the spaced laminae, the ends of the coil are feathered or machined relatively flat. These ends are also bent axially outwardly in order to facilitate the initiation of the in sertion of the spacer within either of the bores. These ends are relatively weak and can be easily distorted, thereby preventing the proper insertion of the coil within the hole.

In applications in which the sandwich is comprised of laminae of relatively heavy gauge, some difliculty has been met in utilizing present apparatus and methods in that there is a tendency to bend or distort the feathered ends of the coils upon insertion. This same efiect also occurs when laminae of conventional thickness are used and a coil of a relatively small wire diameter is used. It is an object, then, of this invention to provide a method and apparatus for installing a coiled spacer between a pair of spaced laminae without distorting the end coils thereof.

It is another object of this invention to provide apparatus and a method for inserting a coiled spacer in between a pair of spaced laminae.

It is an object of this invention to provide a method and apparatus for the insertion of a coiled spacer of the above described type in between a pair of spaced laminae being of a heavy gauge relative to the wire diameter of the coil without permanent distortion or damage to the coil.

Other objects, features, and advantages of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings, in which: 7

FIGURE 1' is a sectional view of a structural sandwich having a spacer assembled therein and a fastener, of lockbolt type, secured to the sandwich;

FIGURE 2 is an elevational view of the spacer applying tool of this invention shown in a position for initially inserting a spacer in the sandwich structure;

3,162,938 Patented Dec. 29, 1964 FIGURE 3 is an elevational view of the tool of this invention shown in a position for completing theassembly of the spacer with the sandwich structure, and illustrating a moved position of the tool in broken lines;

FIGURE 4 is a transverse sectional View of the structure shown in FIGURE 3 looking substantially along the line 4-4; and

FIGURE 5 is an enlarged sectional view of the structure shown in FIGURE 3 looking substantially along the line 55.

Looking now to the drawings, a tool embodying the features of this invention is generally indicated by the numeral 1% and comprises an elongated shaft 12 having a knurled handle 14 on one end thereof. The handle 14 is provided with circumferentially disposed longitudinally extending serrations at its tapered inner end 16. The opposite end of the shaft 12 terminates in a reduced diameter portion 18, having a diameter relative to the diameter of the shaft 12 of a preselected size to form thereby a shoulder 19. The tool 10 is designed for inserting a spring-like helically wound spacer 24 in a sandwich structure 26 which consists of spaced ends or laminate 23 and 30 which, for convenience of descrip tion, are hereinafter referred to as the near and far laminae 28 and 30 which, for convenience of descripare separated by a low density reinforcing core material 32 which may be formed of a plastic material or a very thin gauge metal and serves the purpose of strengthening the sandwich assembly 26.

As previously discussed, it is desirable to secure various structure along the various portions of the sandwich by means of conventional fastening devices. In the assembly of an angled structure 36 to the sandwich structure 26 by means of a fastener, such as a lockbolt 34 (FIGURE 1) which consists of a pin 35 having a collar 37 swaged into locking engagement therewith, it is necessary to first assemble the spacer 24 within the sandwich structure 26 in order to prevent crushing of the core material 32 and, hence, to prevent permanent deformation of the laminae 28 and 31). Thus, a hole is first drilled through the sandwich structure 26, thereby forming openings or bores 39 and 41 in the laminae 28 and 30, respectively, and an opening through the corresponding core material 32. Next, the core material surrounding the drilled opening is removed to a predetermined increased diameter to form a cavity 38 by the use of a suitable tool such as that shown in the copending application of Harold G. Brilmyer, Serial No. 423,327, filed July 12, 1960. The helically wound spacer 24 is in the shape of a coil spring and has an inner diameter at least equal to the diameter of the openings 39 and 41 such as to permit the insertion of the pin 35 therethrough. Since the spacer 24 has an outside diameter greater than the diameter of the openings or bores 39 and 41 and less than the diameter of the cavity 38, the spacer 24, when located within the cavity 38, provides axial support for the area of the laminae 23 and 30 radially proximate to the bores 39 and 41 and also for the low density core material 32 in that area. In the assembled condition, the coils ofthe spacer 24 are maintained axially solid, with adjacent coils being in contact with each other, for providing thereby a total axial length substantially equal to the spacing between the laminae 28 and 31) with the result that the axial load on a fastener such as the lockbolt 34 is reacted by the laminae 28 and 30 and the spacer 24, hence preventing the crushing of the low density core material 32.

V In the use of the tool 19 to assemble the spacer 24 within the cavity 38 in the sandwich structure 26, the spacer 24 is mounted on the shaft 12 with the serrations 16 in engagement with one end 42 of the spacer 24. The shaft 12 is extended through the bores 39 and 41 and the "ice cavity 38 until the opposite end 44 of the spacer 24 is in engagement with the near lamina 28. The tool 14! is then rotatably manipulated such that the end d4 of the spacer 24 is tbreadedthrough the opening 39 in the lamina 28. Hand pressure is exerted axially on the handle 14 concurrently with the rotation of the handle to thereby urge the spring member or spacer 24- into the bore 39. Note that, as the handle 14 is rotated, the serrations 16 engage the end 42 of the spacer 24 and several of the adjacent coils of the spacer 24 in order to thereby urge the spacer 24 to rotate with the handle 14. In practice, three coils laminae 28 and St the tool 19 is then completely Withdrawn from the sandwich 2s and from the spacer 24 and the shaft 12 is inserted from the opposite end of the structure through the bore 41 in the far lamina 38 into the cavity 38 (FIGURE 3) such that the shoulder 1?, defined by the reduced diameter portion 18 and the end of the shaft 12, is in engagement with the inner side of the lamina 2S and the reduced diameter portion i3 255. It can thus be seen that the spacer 24 and the tool 19 are rotated about the axis of the bores 39 and 41' in 'one direction until the spacer 24 is partially threaded through the bore 39 in the lamina 2-8, and then the tool it], after being inserted'into the cavity 38 frorntthe opposite side of the sandwich 26, is rotated in a generally conical pathrabout the axis of the bores 3 and 41 in an opposite direction, thereby causing the spacer 24 to be moved completely into the cavity 38. i V a Note, then, that With a tool ll? constructed as described, means are provided for efiectively and efliciently inserting a coilrtype spacer 24 between a pair of spaced laminae 28 andfiilrwithout resultant injury to the feathered end portions thereofQ By providing the tool it with the reis in engagement with the surface of the lamina 28 defining the bore 32 (FIGURE 4). This engagement of the shoulder 19 and of the reduced diameter portion 18 with the lamina 28 positively locates the tool it) in operative position for further threading'of the spacer 24 into the structural sandwich 26. With the tool ll located such that the shoulder 19 of shaft 12 bears against the lamina 23 in the manner described, the shaft 12 is then tilted or angled into contact with the surface of the far lamina 39 defining the bore 41 (FIGURE 3). The handle id is rotated in a direction causing it to progressively pull the spacer through the opening or bore 39 in the lamina 23 such that the spacer 24 is continuously threaded into the sandwich structure 26 and into the cavity 38 between the spaced laminae 28 and 39. As can best be seen in FIG- URES 3 and 5, the portion of the shaft 12 adjacent to the reduced diameter portion 18 engages those coils which are located Within the cavity 38 between the laminae 28 and 30 suchthat rotation of the tool 16 in the proper direction exerts a force upon these coils which pulls the successive and remaining coils of the spacer 24 into the cavity 38. Note that, as the last coil located at the end 42 of the spacer 24 is being drawn intorthe cavity 38, the force of insertion is applied, not against that feathered portion, but rather against the plurality of coils already inserted within the space'between the laminae 28 and 3% hence providing for the insertion of the coil 24 without distortion or damage. 7 p

To describe the above action more specifically, the bandle 14 is first physically rotated in one direction to initially thread the spacer 24 partially through the, bore '39 into the cavity 38. Next, upon insertion of the shaft 12 of the tool 10 into the cavity 38 from the opposite or far lamina 30, as previously described, the handle 14 is then swung or rotated to define a frusto-conical path about the axis of the bores 39 and 41 While maintaining contact between the shoulder 19 and the inner surface of the lamina Z3 and maintaining contact between the reduced diameter portion 18 and the surface defining the bore 39 in the lamina 28; at the same time, the end portion of the shaft [2 adjacent the reduced diameter portion 18 is in engagement with those coils of the spacer member 24 which lave been inserted Within the cavity 38 and bears against :he spacer 24 such that, as the handle 14 is swung in its irusto-conical path, the spacer member 2.4 is progressively culled within the cavity 38, Note that the shaft 12 is tree to roll about the periphery of the bore 39 in the amine 30 While the reduced diameter portion 18 is free :0 roll about the periphery of the bore 41 in the lamina of the spacer duced diameter portion 18, efiective guide means are provided whereby the motion of the tool 1% in the insertion is controlled. Without some means to effectively control-the swinging of that end of the shaft E2 of the tool llhit, would be possible for the spacer to a be severely distorted by being moved too far Within the cavity 3 8 suchas to actually'damage the spacer 24 and, hence, destroy its efiectiveness.

The shaft 12 is of a diameter just slightly smaller than the diameter of the bores 39 and 41 such that the maximum gap possible between the shaft 12 and the bore41 inthe far lamina 39 is less than the wire diameter of the coils of the spacer 2.4. Thus another function is served in that, upon locationof the tool 10 for installation of .a spacer 24, only a slight gap'exists between the bore 41 in the far lamina 39 and between the shaft 12. Thus, any tendency for the spacer 24 to be threaded out through the far lamina 39 as it is being installed is prevented.

Note that the axial length of the reduced diameter portion 18 is selected such as to not extend into those coils of the spacer 24 which are yet to be drawninto the cavity 38. Y a

While it will be apparent that the preferred embodiment of the invention disclosed is Well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change Without departing from the proper scope or fair 7 meaning of the subjoined claims.

What is claimed is: 1. For use with a sandwich-like structure comprising a pair of spaced laminae having coaxial openings therethrough, a tool vfor inserting a spring-like spacer coaxially with the openings and in between the spaced laminae com: prising an elongated shaft having a handle at one end and a reduced diameter'portion extending axially from that end of said shaft opposite from said one end and defining a generally flat, continuous shoulder for engaging the peripheral surface of the openings.

2. For use with a sandwich-like structure comprising a pair of spaced laminae having coaxial openings therethrough, a tool for inserting a spring-like spacer coaxially with the openings and in between the spaced laminae comprising an elongated shaft having a handle at one end and a reduced diameter portionextending a preselected distance axially from that end of said shaft opposite from said one end and defining a generally flat, continuous shoulder for'engaging the peripheral surface of the openings is less than the wire diameter of the spacer, said shaft having a handle at one end and a reduced diameter portion extending axially from that endof said shaft opposite rom said one end and defining a generally fiat, continu ous shoulder for engaging the peripheral surface of the openings. a

4. For use with a sandwich-like structure comprising a pair of spaced laminae having coaxial openings therethrough, a tool for inserting a coil spring-like spacer coaxially with the openings and in between the spaced laminae comprising an elongated shaft having a preselected diameter relative to the openings such that the maximum gap possible between said shaft and the openings is less than the wire diameter of the spacer, said shaft having a handle at one end and a reduced diameter portion extending a preselected distance axially from that end of said shaft opposite from said one end and defining a generally flat, continuous shoulder for engaging the peripheral surface of the openings.

5. For use with a sandwich-like structure comprising a pair of spaced laminae having coaxial openings therethrough, a tool for inserting a coil spring-like spacer coaxially with the openings and in between the spaced laminae comprising an elongated shaft having a preselected diameter relative to the openings such that the maximum gap possible between said shaft and the openings is less than the wire diameter of the spacer, said shaft having a handle at one end and a reduced diameter portion extending a preselected distance axially from that end of said shaft opposite from said one end and defining a generally flat, continuous shoulder for engaging the peripheral surface of the openings, said handle terminating in a circumferentially extending, longitudinally serrated tapered portion adjacent said one end of said shaft.

6. For use with a sandwich-like structure comprising a pair of spaced laminae having coaxial openings therethrough, a tool for inserting a, coil spring-like spacer coaxially with the openings and in between the spaced laminae comprising an elongated shaft having a preselected diameter relative to the openings such that the maximum gap possible between said shaft and the openings is less than the wire diameter of the spacer, said shaft having a reduced diameter portion extending axially from one end a preselected distance and defining a generally flat, continuous shoulder for engaging the peripheral surface of the openings.

References Cited by the Examiner UNITED STATES PATENTS 2,094,432 9/37 Pazzano 77-72 2,150,875 3/39 Caminez 29-456 2,199,113 4/40 Peirce 29456 2,210,061 8/40 Caminez 29-240.5 2,584,118 2/52 Forster 29-240.5 2,721,376 10/ 5 5 Showman 29-227 2,804,887 9/ 57 Reck 29-229 X 2,839,823 6/58 Brailcato 29-240.5 3,061,054 10/62 Simmonds 29-227 X WILLIAM FELDMAN, Primary Examiner.

NEDWTN BERGER, Examiner.

UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No. 3,162,938 December 29, 1964 William N. Koeller It is hereby certified that error appears in the above numbered patent req'iiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 23, for "laminate" read laminae line 25, for "which, for convenience of descrip-" read respectively. The laminae 28 and 30 Signed and sealed this lst day of- June 1965.,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Aitcsting Officer Commissioner of Patents 

1. FOR USE WITH A SANDWICH-LIKE STRUCTURE COMPRISING A PAIR OF SPACED LAMINAE HAVING COAXIAL OPENINGS THERETHROUGH, A TOOL FOR INSERTING A SPRING-LIKE SPACER COAXIALLY WITH THE OPENINGS AND IN BETWEEN THE SPACED LAMINAE COMPRISING AN ELONGATED SHAFT HAVING A HANDLE AT ONE END AND A REDUCED DIAMETER PORTION EXTENDING AXIALLY FROM THAT END OF SAID SHAFT OPPOSITE FROM SAID ONE END AND DEFINING A GENERALLY FLAT, CONTINUOUS SHOULDER FOR ENGAGING THE PERIPHERAL SURFACE OF THE OPENINGS. 